Bis(aminomethyl)cyclohexane is an industrially important compound to be used as a raw material for e.g., epoxy hardeners, polyamides and polyurethanes. A bis(aminomethyl)cyclohexane has two isomers, i.e., a cis-isomer and a trans-isomer, derived from the cyclohexane ring. It is known that the physical properties of a polymer obtained by using a bis(aminomethyl)cyclohexane greatly vary depending upon the ratio of isomers, i.e., ratio of a cis-isomer and a trans-isomer.
For example, in a polyamide obtained by using 1,4-bis(aminomethyl)cyclohexane, it is known that, as the content of a trans-isomer increases, the melting point of the polyamide increases, with the result that the polyamide becomes highly heat resistant (Non Patent Literature 1). It is also known that a polyurethane obtained by using 1,4-bisisocyanatomethyl cyclohexane derived from 1,4-bis(aminomethyl)cyclohexane is improved in physical properties required for various applications as the content of the trans-isomer increases (Patent Literature 1).
It is further shown that, in a polyamide obtained by using 1,3-bis(aminomethyl)cyclohexane, a polyamide having a high cis-isomer content has a high crystallinity; whereas a polyamide having a high trans-isomer content is amorphous (Non Patent Literature 2).
For these reasons, it is extremely important to control the isomer ratio of a bis(aminomethyl)cyclohexane.